1. Field of the Disclosure
The disclosure refers to a helium sensor comprising a detection chamber having a wall selectively permeable to a tracer gas, an ion getter pump having at least one cathode and at least one anode which are connected to a voltage source, and a magnetic field generator which generates a magnetic field extending across the detection chamber.
2. Discussion of the Background Art
A helium sensor of this type is described in DE 100 31 882 A1 (Leybold Vacuum GmbH). The detection chamber is made of glass and the wall selectively permeable to the tracer gas helium is a silicon disc provided with perforations that are each closed by means of a thin quartz membrane, the disc comprising a special heating. Such a gas sensor is also referred to as a quartz window sensor because of the nature of the selectively permeable wall. The gas atoms that have passed the selectively permeable wall are ionized in the detection chamber and are led to a cathode by an electrical field, where they are bound.
A similar helium sensor is described in DE 10 2004 034 381 A1 (Inficon GmbH).